I am an investigative journalist with an emphasis on data journalism, undercover secret filming work and good old fashioned digging. I love a leaked document or database – there are few feelings like knowing you are on to a corker of a story and when it’s broadcast there’ll be a big fallout. My work has featured on BBC programmes including Panorama, Newsnight, File on 4 and the national News at Six. Here you can find some of the stories I’m most happy with from the last few years. I am currently in the Special Investigations team at Global Witness, working to expose grand corruption, environmental destruction and human rights abuses in some of the world’s most troubled countries. In the mix with all the hard news are features on history and travel I’ve written too and a documentary about voodoo sorcery I presented on the BBC World Service.

When a £27 million investment scheme that supposedly made huge profits through a clever gambling loophole went bust, I began to investigate. It was promoted by the Premiership footballer Steve Claridge (who denied all wrongdoing). Careful data journalism showed the claimed rates of return could not be possible. Here’s my report on Radio 4.

What’s the most expensive object ever built? I went on a statistical journey for Radio 4’s More or Less programme from the Great Pyramid of Giza to the International Space Station, via the Great Wall of China and a rather pricey nuclear reactor.

I exposed the cosmetics shops willing to deal in illegal skin whitening cream, containing a banned chemical that can damage the liver and nervous system. Staff were placing products on shelves they knew to contain the active ingredient, despite it not being listed on the ingredients. That means unwilling customers who thought they could trust something displayed openly were put at risk. Watch the film for my maiden doorstep!

Our investigation exposed the self-styled ‘Reverend’ who believes you can cure everything from aids to Alzheimer’s by making patients swallow doses of bleach – and the US cult-style ‘church of healing’ from which he takes inspiration. I have encountered some wacky characters during my time as a journalist, but this lot took the biscuit. Mind-boggling stuff.

More than 100 security guards had their licences revoked after our undercover investigation revealed they had been obtained fraudulently. Police are investigating the 251 individuals currently implicated in what one security expert called an “astounding” fraud.

Say hello to a “profiteering” care agency boss who took hundreds of pounds from low-paid carers who were desperate to work for jobs that never materialised. One ripped off worker said: “They sold me dreams and made promises they didn’t keep.”

Blind people refused by minicab drivers who won’t allow a guide dog on board their vehicle? Surely not! Sadly yes. We documented shocking treatment of the blind people and wheelchair users in twenty-first century London.

Had your mobile phone nicked in London? These are the guys who enable a crime that can shatter peoples’ confidence and feelings of security. We went undercover to expose a black market of shops willing to deal in the stolen devices. The Metropolitan Police subsequently raided the businesses we caught.

Another one of the most shocking investigations I have ever worked on: the London estate agents who refused black tenants because of the colour of their skin. This exposé was all over Fleet Street and was subsequently named the best investigation in Europe at the 2014 Circom Awards. Like so many of the stories I have worked on, the lion’s share of credit must go to my enormously talented and determined colleague, Guy Lynn. He is one of the best investigative reporters working in the UK today.

After the killing of Lee Rigby in Woolwich, I found a banned Islamic scholar’s texts on offer to the public… at Woolwich Public Library. Dr Zakir Naik was barred from the UK in 2010 by the Home Secretary. One chapter was entitled: “The inequality of male and female witnesses.”

In it Dr Naik argued a male testimony is worth that of two females in financial matters. The story was reported prominently in the Daily Telegraph.

It’s not only methadone given to drug addicts by the NHS – some are even prescribed heroin. Not many people knew that.

How Newham Council spent a whopping £111m on its new headquarters… including £1,800 on individual, designer light fittings. This in what is one of the poorest boroughs in the UK. The exclusive was followed up on the front page of the Metro and in the Sunday Times. Newham Council insists to this day that its headquarters – which cost a full third as much Arsenal’s world famous Emirates Stadium – actually saves taxpayers money.

A difficult but important piece of data journalism, showing for the first time how prevalent polyethylene-based cladding – as used on Grenfell Tower – is across the UK. At least 52 tower blocks in London utilise the material.

A big piece of data journalism I did on the hoary old topic of parking enforcement – the revelation that £23m of parking tickets awarded by London councils may have been unlawful.

A piece I wrote for the Mail on Sunday about the joys and hardships of travel in Ethiopia, not least the hair-raising ascent to the Monastery of Debre Damo (pictured). The monastery – accessible only by a rope-lift up vertiginous cliffs – is a major location in my debut novel, Foretold by Thunder.

Piece of data journalism showing how councils across the UK used litter fines as a ‘cash cow’. This exclusive was followed up with a front page story in the Daily Mail.

Back in 2011, my friend Jafar Habib, from Ghana, told me something amazing. At the annual festival of voodoo in nearby Benin, he saw a voodoo sorcerer cut off a woman’s head and reattach it… whereupon she came back to life. Six years on, I returned with him to Benin, seeking out the most powerful sorcerers in the land to bear witness to their magic and confront Jafar’s own beliefs and preconceptions about voodoo. This radio documentary I presented for the BBC World Service is the result. Warning: disturbing content may upset some people.

One of my involvements in the case of the corrupt Mayor of Tower Hamlets, Lutfur Rahman. We revealed claims that employees of his council were threatened with the sack if they did not each illegally obtain 100 votes for the disgraced politician. I was in the High Court to see him face justice – sheer courtroom drama.

This may just be the single most astounding story I’ve ever worked on. Corrupt Flying Squad officers plotted to kidnap the partner of a cash van driver and hold her to ransom. The plot was foiled by Met anti-corruption police – but neither of the intended victims was told. Details of the case were then revealed in a cache of police intelligence reports the Met thought they’d shredded, but were obtained by my colleague Glen Campbell, an old school investigative reporter and expert on police corruption. I tracked them down nearly twenty years later – the female victim now living in the Gambia – and told them what had happened.

What is the life of an illegal labourer in London really like? Before Romanians got the right to work in the UK, we penetrated a murky and dangerous world to highlight the slave labour wages and appalling conditions endured by desperate workers. A difficult investigation in which potential risks to our undercover operatives were at the forefront of our minds.

I reported from Woolwich the day after Lee Rigby was slain by Islamic extremists. The atmosphere was tense and sombre and rather scary.

Our undercover investigation into dodgy pharmacists revealed no less than nine independent pharmacies willing to selling powerful drugs including opiates and Valium over the counter for cash. SFollowed up by the Daily Mail and the London Evening Standard.

Update: Three years on, and nine of the pharmacists we exposed have been banned from practise. The General Pharmaceutical Council used our investigation to appeal for greater powers from the government, and as a result expects to be able to carry out its own covert surveillance of rogue pharmacists. http://www.bbc.co.uk/news/uk-england-london-35720655

The UK Border Agency – then branded “not fit for purpose” – gave its staff more than £3.5m of taxpayer’s money in bonuses in a single year. The Times picked up this story and were good enough to credit our digging.

One of a series of stories I worked on with Kurt Barling following the entirely avoidable fire at Lakanal House tower block in Southwark, which killed six. Fashion designer Catherine Hickman died after being told to stay in her flat by firefighters. Those that ignored the advice lived. She was found with her phone in her hand. An awful tragedy.

One of the stories I am proudest of, and the scoop that set Kurt and I off on a several-year long exposure of the shocking fire safety in London’s social housing stock. Following a paper trail of old reports and documents, I discovered Southwark Council knew Lakanal House was a fire hazard – but did nothing to make it safe. Among the lives lost there were one father’s entire family. His wife, son and daughter all perished.

Here Mr Barling and I revealed that more than 300 high rises in London had not even been checked for fire safety by the authorities. This precipitated every tower block in London that had not been risk assessed rapidly having one done. It is not out of the realms of possibility that this story saved lives.

I went undercover for BBC Panorama posing as a desperate would-be dad to investigate how a top end fertility clinic sells expensive IVF add on treatments … with limited evidence they actually work.

We exposed the scam colleges willing to sit exams for students for cash, enabling them to become bouncers and bodyguards without a bit of training. A fraudulent license obtained by our researcher was used to obtain an offer of work at a power station and an interview to guard Canary Wharf. This piece made the national News at Six on BBC1, Radio 4, Five Live and the Daily Telegraph.

The hand in the photograph belongs to the Porsche-driving boss of a training centre in west London. He is reading answers from a big screen to labourers so they can cheat a test in building safety, thus becoming licensed to work on any site in the country. Construction is the UK’s most deadly industry – during the Afghan war more of our builders were killed than British soldiers. This was one of several firms we busted. The investigation ran as a 13 minute film on Newsnight and as a result of our enquiries 6,000 labourers have been forced to resit fraudulent exams. As the film went to air, the editor of Newsnight tweeted: “If Carlsberg did bad guys they would be this fake safety qualification guy.” Why was he flagrantly putting lives at risk in this way? To paraphrase Fargo: for a little bit of money.

Beware online adverts for properties to rent that look too good to be true. They might just have been uploaded from a Nigerian scam artist! We exposed two such ne’er-do-wells… and revealed a steep rise in cases of the fraud.

I went undercover as a raver to highlight the blatant use and abuse of laughing gas at SW4 Festival in Clapham. At one point we filmed four girls I estimated to be no more than 13 consuming the drug, as a security guard looked on and did nothing. Enough to put your head into a spin.

Journalists who did far more than I to expose the Mayor of Tower Hamlets Lutfur Rahman include: Andrew Gilligan, John Ware, Ted Jeory. But here is another of my minor additions to a formidable body of investigative reportage. Witnesses in the court case that eventually saw him overthrown were allegedly intimidated – including purported threats to their families in Bangladesh.

Some of the UK’s biggest firms promised to up their game after we revealed potentially illegal failures to accommodate disabled people. Itsu, Costa Coffee, Eat and Caffé Nero were among the companies to launch immediate improvement programmes. (Fair play to them for acting so decisively.)

The scam artist we caught selling pirated Sky TV was confronted in what one colleague described as “doorstep ballet”. Reckon it’s a victimless crime? Think again. The money lost to broadcasters because of this fraud could be invested in new drama, paying the wages of struggling actors and writers.

We obtained a bombshell report showing that TfL knew the Hammersmith Flyover could collapse at any moment – yet left it open to traffic. You’ve gotta love it when organisations helpfully write ‘restricted’ all over a leaked report. I worked with Rebecca Cafe on this story.

Along with the brilliant journalist Zack Adesina (whose baby this story was) I imported illegal stun guns some twenty times more powerful than those the police use into the UK. Ordered online, they sailed through customs… and even came with a free pepper spray!

As parking stories go, this was a jolly good one. A London council illegally set its traffic wardens minimum quotas of parking tickets to achieve, with predictable results. Another of those glorious ‘leaked document’ stories I am so fond of. I remember rushing to get this to air before flying to Ethiopia to research Foretold by Thunder…

Patients at an east London hospital were left with life-changing injuries due to a lack of resources, we revealed in 2011. Some five surgeons resigned in protest about the problems at the hospital. Big cap-doffing to BBC London’s doughty Political Correspondent Karl Mercer for his digging on this one.

Our investigation into the fire safety of London’s tower blocks following the Lakanal disaster found some 102 inhabited buildings considered even more dangerous than the killer high rise.